The present invention relates to a method for performing diagnostic of an actuator comprising a coil and a control device of power supply of the coil, in particular an electric circuit breaker actuator. It also relates to a device for performing diagnostic of the power supply of a coil of an actuator enabling the diagnostic method to be implemented. It also relates to an actuator comprising a coil and at least one such diagnostic device. It finally relates to a computer program comprising computer program code means suitable for execution of steps of the diagnostic method.